Good idea
Combining RGB colors to match with the target is a really great idea, but maybe this would be better if it was for example, a minigame for a much larger game, rather than a whole game of just trying to match the target color. The graphics were amazing, and there could've been some music or sound affects since it's currently completely silent. A few more levels would've hurt, i guess.
And by the way, i think the game froze, because when I clicked start, since it went black, and I had to right-click and click play so it would actually work. I'd suggest maybe fixing that.
Overall the game was a good idea, but it could've been better. But, good job anyways :)